HP in particular has done their best to copy the MacBook's design language down to blatant touches like a lit logo on the lid. It doesn't make the MacBook any less distinctive. Imitation is the sincerest form of flattery.
That said, I'm fairly certain that the hugely overblown backlash to the black finish on the iPhones (I say overblown because mine is going on 6 months old without a single visible nick, though obviously this is anecdotal) is going to prevent them from attempting this on a product with 100x the surface area. Which is just fine with me, since I feel that an all-black computer would lack the contrast that makes the MacBook design so attractive.